Alt-BEAM Archive
Message #05883
To: beam@sgiblab.sgi.com
From: Bruce Robinson Bruce_Robinson@bc.sympatico.ca
Date: Wed, 25 Aug 1999 23:37:01 -0700
Subject: [alt-beam] Re: New Guy Questions
Ben Hitchcock wrote:
>
> ... if you are going to use a 74HC139 chip
> to protect the H-bridge, then why not just
> use that (or similar) chip as the motor driver?
Power, pure and simple. 74HC-series chips can typically handle 20 mA.
Driver chips in the series are good for 50% more. The H-bridge
transistors I use can handle 500 mA.
Since I'm never exactly sure what I might end up using to power my
robots, I play it safe and spend an extra dollar. But, yes, space is
certainly a consideration.
Bruce
5884 Thu, 26 Aug 1999 12:17:06 EDT [alt-beam] test beam@corp.sgi.com NetRat66@aol.com
5885 Thu, 26 Aug 1999 17:29:30 -0400 Re: Solarbotics Miniball Kit for Sale beam@sgiblab.sgi.com owner-beam@sgiblab.sgi.com [mailto:owner-beam@sgiblab.sgi.com]On
At 01:34 PM 8/11/99 , Lee Golden wrote:
>Hi --
>
>I bought a Solarbotics Miniball kit several months ago, but have yet to
>get around to building it. The kit is complete and unbuilt including
>the custom made hand built gear motor!
>
>MY cost was $160.00, but I am willing to entertain cash/trade offers
>for it. Just not enough time to do everything I want to...sigh.
Mr. Golden, if you want to return it, we'd be happy to oblige you!
Regards,
Dave
---------------------------------------------------------------
"Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
2 vowels. Pronounciation? _SMITH_".
http://www.solarbotics.com
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